Add description and usage to README

Author: garaujodev

README.md

@@ -1,11 +1,19 @@
 # AutoFormatter
 
-**TODO: Add description**
+This package have the responsibility to run `mix format`
+after **EVERY** commit to ensure that you modified code
+is formated.
 
 ## Installation
 
-If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `auto_formatter` to your list of dependencies in `mix.exs`:
+The best way to install this package is install it as a escript:
+
+```bash
+mix escript.install hex auto_formatter
+```
+
+Otherwise, this package can be installed by adding `auto_formatter` to
+your list of dependencies in `mix.exs`:
 
 ```elixir
 def deps do
@@ -14,8 +22,17 @@ def deps do
   ]
 end
 ```
+Then, run `mix deps.get` on your terminal to download it.
+
+## Usage
+
+All that you need is init it:
+
+```bash
+autoformatter init
+```
 
-Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
-and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
-be found at [https://hexdocs.pm/auto_formatter](https://hexdocs.pm/auto_formatter).
+## Documentation
 
+The docs can be found at
+[HexDocs](https://hexdocs.pm/auto_formatter).